High blood pressure may lead to brain injury and to premature brain aging, even among people with only slightly elevated readings.

Brain scientists from the Alzheimer’s Disease Center at the University of California, Davis, are studying the links between systolic blood pressure (that’s the first number in a reading, and measures the pressure of the blood on the vessels as the heart beats) and various indicators of brain injury among middle-aged adults. In their latest work, published in Lancet Neurology, the scientists report “a subtle, negative effect” of high systolic blood pressure on the structural integrity of the brain’s white matter, and a similar negative effect of elevated blood pressure on the volume of grey matter in the brain.

That means that by age 40, the brain of a person with hypertension or clinically high blood pressure of 140/90 mm Hg, looks 7.2 years older than the brain of a person with normal blood pressure, according to indicators of brain function and anatomy that the researchers measured. And it’s not just those with clinical hypertension who have to worry; the team saw changes in brain structure among people with normal blood-pressure readings or with systolic readings just slightly higher than normal. The higher the systolic blood pressure, it seems, the greater the signs of brain damage.

These findings are consistent with previous research that links hypertension to brain damage. But this is the first study to show an association beginning so early in life. This study finds the same kind of structural injuries that have been linked to cognitive decline and increased risk of dementia among elderly people, but instead among those in just their 30s and 40s.

“The message here is really clear: People can influence their late-life brain health by knowing and treating their blood pressure at a young age, when you wouldn’t necessarily be thinking about it,” said Dr. Charles DeCarli, senior author on the study and the director of the UC Davis Alzheimer’s Disease Center. “The people in our study were cognitively normal, so a lack of [cognitive-decline] symptoms doesn’t mean anything.”

To conduct their study, DeCarli and colleagues looked at blood-pressure readings and brain scans from 579 people, aged 19 to 63, participating in the Framingham Heart Study. Running since 1948, Framingham is probably the single most important study ever conducted on heart disease risk factors. Over the years, it has revealed the role of obesity, high blood pressure, and high cholesterol in determining heart-disease risk – all things that, today, we take for granted as common knowledge. Framingham is now helping to reveal the role that heart health plays in cognitive performance as well.

DeCarli’s research shows that measurable brain injury can occur decades before clinical signs of dementia appear. And, with ever-stronger evidence for a linkbetween heart healthand brain health, the new findings suggest that all adults, not just the elderly, should be vigilant about managing their blood pressure.

Although only a doctor can diagnose hypertension, it’s worth monitoring your own blood pressure occasionally, either at drugstores, which offer free checks, or with an at-home reader. That way, you can compare daily measurements to those taken at your routine or emergency medical visits.

Hypertension is extremely common. The U.S. National Heart, Lung, and Blood Institute estimates that two thirds of Americans over 65 now have high blood pressure. Readings between 120/80 mm Hg and 139/89 mm Hg are considered signs of “prehypertension,” with anything above 140/90 mm Hg qualifying as hypertension. Blood pressure, particularly the systolic reading, tends to rise with age, so higher mesurements early in life are a potential danger sign, say experts. And according to this latest research, the harms to your brain may begin well before your golden years if hypertension isn’t controlled properly. As the researchers write in their journal article, the evidence of even subtle brain injury among young middle-aged people “should have a substantial impact on how physicians regard hypertension diagnosis and treatment […]. [P]revention of stroke or cognitive impairment due to hypertensive vascular disease may require treatment at younger ages than currently envisioned.”